Posted in Biology

Download e-book for kindle: Active Transport through Animal Cell Membranes by P.G. LeFevre

By P.G. LeFevre

ISBN-10: 3211803874

ISBN-13: 9783211803875

ISBN-10: 3709157684

ISBN-13: 9783709157688

Show description

Read or Download Active Transport through Animal Cell Membranes PDF

Similar biology books

Extra resources for Active Transport through Animal Cell Membranes

Example text

However, the action of the intracellular K + level is probably not so much on phosphate-transfer processes as on synthetic activities; the incorporated P is not readily lost again, more than a mere translocation being involved. Glucose, fructose. or galactose assist in the phosphate uptake in this system, but G-l-P, G-b-P. or F-b-P are not effective. Table X. Phosphate Uptake and :lletabolic Activity in Bremer's Yeast. (Modified from NICKERSON. ) Additions to glucose· phosphate medium Uptake (arbitrary units) p32 I I I I· None DNP, 5· 10-~ M.

The double treatment given to K + in the kidney tubule probably involves different loci. In a recent review of the subject, MUDGE (1954) calls attention to the micropuncture work of Bott on the Necturus kidney, whidl shows directly that the filtered K + is actually nearly completely reabsorbed in the proximal tubule, only to be replaced by active tubular secretion in the distal tubule. -According to CONWAY, FITZGERALD, and MACDOUGALD (1946), the proximal tubular cells of the isolated frog kidney can accumulate very high concentrations of K+ when an excess of this ion is supplied in the medium; but these cells are essentially impermeable to Na+, thus falling into the BOYLE-CONWAY pattern as originally developed for muscle cells.

Both pyruvate and ATP. 05 Anaerobic; no addition pyruvate, 5 mM. . . ATP, lmM . . . both pyruvate and ATP. 37 "Cyclophorase" (nuclei and mitochondria) Mitochondria Untreated; 0° C . ketogluterate, 5 mM. . and incubated 15 min. at aerobically . anaerobically . . . 1 0° C.. . :Wu C. . Na+ is here removed from medium, while almost none is lost from particles. "Cyclophorase" preparations all incubated 30 minutes at 20°C. 5 mM. ~aHC03 STANBURY and MUDGE (1953) attempted to analyse the relation of the mitochondrial K+ maintenance to the metabolic activity in similar preparations from rabbit liver.

Download PDF sample

Active Transport through Animal Cell Membranes by P.G. LeFevre


by Jason
4.3

Rated 4.90 of 5 – based on 6 votes